Substituted benzenesulphonamido-thiazolines



Us. Cl. 260-306.7

United States Patent 3,505,347 SUBSTITUTED BENZENESULPHONAMIDO- THIAZOLINES Jacques Baetz, La Garenne-Colombes, France, assignor to Seperic, Morat, Switzerland, a Swiss body corporate No Drawing. Filed Nov. 14, 1966, Ser. No. 593,724 Claims priority, application Great Britain, Nov. 19, 1965, 49,171/ 65 Int. Cl. C07d 91/14, 91/26 6 Claims ABSTRACT OF THE DISCLOSURE Benzenesulphonyl-2-amino-A-2-thiazolines monodior tri-substituted on the benzene ring by chlorine or fluorine atoms or lower alkyl groups. These compounds have antibacterial activity.

The present invention concerns a family of novel chemical compounds having useful therapeutic properties and, in particular, a substantial antibacterial activity useful in humans for the treatment of infectious conditions.

Said compounds are sulphonamides of general formula:

wherein substitutents R, R and R which may occupy any one of the free positions of the benzene nucleus and which may be the same or different, are each hydrogen, a chlorine or fluorine atom or an alkyl group having 1-4 carbon atoms, and their addition salts with pharmaceutically acceptable acids.

Preferably, all three substituents R, R and R are not simultaneously hydrogen and, when one of them is a methyl group, one at least of the other two is not hydrogen.

It is known that aminothiazoline structures of the type illustrated by Formula I are conventionally equivalent to the iminothiazolidine structures of the type illustrated by Formula II. This explains the dual character of formulae within the definition of the present compounds. For purposes of simplicity, such compounds will be considered hereinafter as corresponding to structure (I) and thus as benzenesulphonyl-Z-amino-A-2-thiazolines which are, if desired, susbtituted on the benzene nucleus. This, however, should not be considered as limitative as to the actual structure of the compounds, the existence in their infrared spectra of a vibration for an extra-cyclic @NH grouping seeming, furthermore, to be in favour of structure (II).

To prepare such compounds, the benzenesulfochloride suitably substituted on the benzene nucleus, of general formula:

is reacted with the 2-amino-A-2-thiazoline and the resulting sulphonamide is, if desired, salified.

The reaction is advantageously effected by contacting an alkaline aqueous 2-amino-A-2-thiazoline solution with an organic benzene sulphochloride solution. The reaction occurs readily Without heating and, on the contrary, it is sometimes advisable to refrigerate with an ice bath, for example.

A typical procedure is as follows:

In a vessel are introduced, with stirring, 2-amino-A-2 thiazoline base dissolved in an alkaline aqueous solution such as a 6% w./v. sodium hydroxide solution or an alkali metal carbonate solution.

An equimolar (or slightly higher) amount of benzene sulphochloride suitably substituted on the benzene nucleus dissolved in an organic solvent (benzene, toluene, carbon tetrachloride, etc.) is added with stirring.

In a modified procedure the Z-amino-A-Z-thiazoline is used as a solution in water and the alkaline product is added after addition of the benzene sulphochloride solution.

When this step is complete, one insures that the solution is still alkaline, and the resultant product is precipitated in the cold by maintaining the solution in the refrigerator, for example. There results a precipitate that is suction filtered, Washed with water and then dried in air and which may be recrystallized from alcohol or a suitable solvent.

The sulphonamides thus obtained may be converted, conventionally, into pharmaceutically acceptable inorganic or organic acid salts. Thus, for example, hydrochlorides may be produced therefrom, in water/ alcohol media, and there are obtained crystalline products, often containing one mole ethanol, exhibiting improved water-solubility.

The following examples are given for the purpose of illustrating such preparation.

EXAMPLE 1 4' chloro-3-methyl-benzenesulphonyl-Z-amino-A-2-thiazoline or 3-methyl-4'-chloro-benzenesulphonyl-3-2-imino thiazolidine (both structures being equivalent) The empirical formula of this compound is C H O N S Cl and its molecular Weight is 290.803. The preparation thereof is effected as follows:

In a conical 500 ml. flask provided with a magnetic stirrer, are introduced 61 g. Z-aminO-thiazoline base dissolved in sodium hydroxide (24 g. in 150 ml. water); to this are added dropwise, with stirring, 135 g. 4-chloro- S-methyl benzene sulphochloride dissolved in 60 ml. toluene. The solution is stirred for a further 30 minutes in an ice bath. It is left one hour in the refrigerator. It is then suction filtered and dried in vacuo. Recrystallization is effected from hot alcohol. There is obtained a product which, on cooling, produces a precipitate which is dried in vacuo.

Melting point (capillary tube)-118-120 C.

Nitrogen percenttheory: 9.66; found: 9.20.

Carbon percenttheory: 41.13; found: 40.71.

The hydrochloride of this sulphonamide is prepared by dissolving 10 g. 4-chloro-3'-methyl-benzenesulphonyl-Q- amino-A-Z-thiazoline in ml. ethanol, in the hot. The resultant solution is filtered; it is then cooled to incipient crystallization, and gaseous hydrochloric acid is then bubbled through to saturation. The hydrochloride crystallizes on cooling. This is suction filtered, and washed with 2X 10 ml. cold ethanol.

The material is dried in vacuo in the presence of potassium hydroxide.

There are obtained 9.5 g. of 4'-chloro-3 methyl-benzenesulphonyl-2-aminoA-2-thiazoline hydrochloride.

Yield: 74%.

Melting point (capillary tube): 191-193 C. The product crystallizes with one mole ethanol.

Nitrogen percenttheory: 7.03; calculated: 7.50. Carbon percenttheory: 38.08; calculated: 38.61.

EXAMPLE 2 4'-chloro-benzenesulphonyl-Z-amino-A-Z-thiazoline or 4- chloro-benzenesulphonyl-3,Z-imino-thiazolidine In 125 ml. water there are dissolved 20.4 g. (0.2 mole) Z-amino-A-Z-thiazoline. The solution is refrigerated, with stirring, in an ice bath, and a solution of 42.4 g. 4-chlorobenzenesulphochloride dissolved in 50 ml. benzene is then added.

When the temperature reaches C., 20 ml. soda lye diluted to 100 ml. are added over 20 minutes, the temperature being maintained below 10 C. The sulphonamide precipitates out. Stirring is continued for a further minutes.

The material is suction filtered on a Buchner funnel. It is washed with 3X50 ml. water, and once with 50 ml. petroleum ether.

There are obtained 31.5 g. 4-chloro-benzenesulphonyl- 2-amino-A-2-thiazoline.

Yield: 57%.

Melting point (capillary tube): 9899 C.

Nitrogen percent-theory: 10.11; found: 10.09.

Carbon percenttheory: 39.30; found: 38.24.

The crude product is recrystallized from absolute ethyl alcohol, with heating followed by cooling.

Crystallization yield: 70%

To prepare the sulphonamide hydrochloride, g. 4'- chloro-benzenesulphonyl-Z-amino-A-Z-thiazoline are dissolved in 20 ml. absolute ethanol in the hot. The reaction mixture is filtered; it is then cooled and gaseous hydrochloric acid is bubbled through to saturation. On cooling, the hydrochloride crystallizes out as fluffy crystals.

The material is dried in vacuo in the presence of potassium hydroxide. There are obtained 15 g. 4-chloro-benzenesulphonyl-2-amino-A-Z-thiazoline hydrochloride.

Yield: 66%.

Melting point: 104 C.

The hydrochloride crystallizes with one molecule of alcohol.

Nitrogen percent-theory: 7.55; found: 7.80.

Carbon percent-theory: 36.30; found: 36.77.

The physical-chemical properties of the compounds according to Examples 1 and 2 and of other compounds according to the invention prepared in a similar manner are summarized in the table below:

With the novel sulphonamides, incomplete inhibition is noted at 1.40 mg./ml. culture medium and complete inhibition with 2 mg./rnl. culture medium whereas, under the same conditions, sulphamethyl-thiadiazole inhibits the growth of colibacillus incompletely at 2 rug/ml. and completely at 2.80 rug/ml.

On the other hand, in vivo, the death rate in mice, due to different germs, and particularly to colibacillus, is more reduced by these novel sulphonamides than by sulphamethylthiadiazole at the same dosage.

In addition, 4'-chloro-benzenesulphonyl-Z-amino-A-Z- thiazoline was found to have diuretic properties that are particularly useful in the treatment of colibacillosis the pathological effect of which is chiefly apparent in the urinary system.

These results were confirmed by experimentation in human clinics; thus, the novel sulphonamides are therapeutically useful in infectious conditions.

For such use, the sulphonarnides may be administered orally or parenterally in the form of therapeutic compositions containing the usual vehicles and excipients suitable for such routes of administration.

Thus, for oral administration, the sulphonamides may be formulated in unit dosage form containing from 100 to 500 mg. of sulphonamide. For parenteral administration, a suitable form is a sulphonamide solution in an injectable organic solvent, the therapeutic composition being, for example, in the form of 2 ml. ampoules containing 500 mg. of sulphonamide.

The novel sulphonamides may be administered generally to adults at a daily dosage regimen of 500 mg. to 2 g.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Sulphonamides of general formula selected from Melting Nitrogen percent Carbon percent point, 0. Molecular (capil- Oalcu- Calcuweight lary tube) lated Found lated Found 4-chloro-benzenesul hon l-Z-aminothia-zoline f. f 276. 776 98-99 10. 11 10. 09 39. 06 38. 24 3-chloro-4-rnethyl-benzenesulphonyl-Z- ammo-A-2-thiazoline 290. 803 87-88 9. 63 9. 86 41. 30 41. 37 3',5-diehlor0-4-rnethylbenzenesulphonyl- 2-amino-A-2-thiazoline 325. 252 154-156 8. 61 8. 02 36. 93 37. 05 2,3-diehloro-6-methy1-benzenesulphouyl- 2-amino-A-2-thiazoline 325. 252 137-139 8. 61 8. 05 36. 93 37. 41 2,3-dimethyl-6-chloro-benzenesulphon 1 Z-amino-A-Z-thiazoline 304. 829 144-146 9. 18 9. O4 43. 34 43. 34 3,6-diehloro4'-methyl-benzenesu1phonyl 2-amino-A-2-thiazoline 325. 252 154-160 8. 61 8. 42 36. 93 37. 48 4'-ehl0m-3-methyl-benzenesulphonyl-Z- amino-A-Z-thiazoline 290. 803 118-120 9. 63 y 9. 20 41. 30 40. 71 4-fluoro-benzenesulphonyl-2-amino-A-2- thiazoline 260. 319 94-96 10. 76 10. 63 41. 53 41. 74 2,5-dieh1oro-benzenesulphonyl-2-aminoA- 2-thiaz0line 311. 225 132-134 9 8. 92 34. 73 34. 90

As mentioned above, the novel sulphonamides have unique antibacterial properties that were made apparent by both in vitro and in vivo investigations.

Thus, in vitro, under similar experimental conditions, 4-chloro-3-methyl-benzenesulphonyI-Z-amino-A 2 thiazoline and 4'-chloro-benzenesulphonyl-Z-amino-A-Z-thiazoline were found to inhibit the development of pathogenic colibacillus, at lower concentrations than required by sulphamethylthiadiazole, a currently widely used anticolibacillary sulphonamide.

wherein substituents R, R and R which may occupy any one of the free positions of the benzene nucleus, are each selected from the group consisting of hydrogen, chlorine and fluorine atoms and :alkyl groups having 1-4 carbon atoms, provided that the substituents R, R and R are not simultaneously hydrogen and, when one of the substituents is a methyl group, one at least of the other two is not hydrogen, and their addition salts with pharmaceutically acceptable acids.

2. 4'-chloro-benzenesulphonyl-Z-amino-A-2-thiazoline.

3. 3' chloro 4 methyl benzenesulphonyi-Z-amino- A-Z-thiazoiine.

4. 3,6 dichloro 4' methyl-benzenesulphonyl-Z- amino-A-Z-thiazoline.

5. 4 chloro 3' methyl-benzenesu1ph0nyl-2-amin0- A-Z-thiazoline.

6. 4' fiuoro-benzenesulphonyl 2 amino-A-Z-thiazoline.

References Cited UNITED STATES PATENTS 2,524,800 10/1950 Holtquist et a1 260306.7

6 OTHER REFERENCES Burger: Medicinal Chemistry, 2nd ed., Interscience,

Elderfield: Hetercyclic Compounds, v01. 5, Wiley, 1957 Jensen et aL: Chem. Abstracts, 3S:510910 (1941).

ALEX MAZEL, Primary Examiner U.S. C1. X.R. 

